Compound K attenuates glucose intolerance and hepatic steatosis through AMPK-dependent pathways in type 2 diabetic OLETF rats.

BACKGROUND/AIMS: Non-alcoholic fatty liver disease is associated with insulin resistance. Compound K (CK) is the final metabolite of panaxadiol ginsenosides that have been shown to exert antidiabetic effects. However, the molecular mechanism of the antidiabetic effects in the liver have not been elucidated; further, whether CK has beneficial effects in hepatosteatosis remains unclear. Therefore, we evaluated the effect of CK on hepatosteatosis as well as its mechanism in high-fat diet (HFD)-fed type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS: Twenty-four-week-old male OLETF rats were assigned to four groups: control (saline), CK 10 mg/kg, CK 25 mg/kg, or metformin 300 mg/kg (positive control); all treatments were administered orally for 12 weeks. RESULTS: Fasting glucose levels of the CK25 group were significantly lower than those of the control group during the 12 weeks. The results of the oral glucose tolerance test showed that both the glucose concentration after glucose loading and the fasting insulin levels of the CK25 group were significantly lower than those of the control. Hepatosteatosis was significantly improved by CK25. CK25 and metformin significantly increased the phosphorylation of hepatic adenosine monophosphate-activated protein kinase (AMPK). CK25 significantly inhibited the expression of sterol regulatory element-binding protein-1c and fatty acid synthase, while upregulating that of peroxisome proliferator-activated receptor-α and carnitine palmitoyltransferase-1. CONCLUSIONS: CK improved glucose intolerance and hepatosteatosis in HFD-fed OLETF rats through AMPK activation, which has dual mode of action that involves decreasing the synthesis of fatty acids and increasing fatty acid oxidation.

A case of possible neurosarcoidosis presenting as intractable headache and panhypopituitarism.

Sarcoidosis is a chronic multisystemic inflammatory disease of unknown etiology, which is characterized by noncaseating granulomatous inflammation of the involved organs. It is known that neurosarcoidosis involving the nervous system occurs in about 5% of patients with sarcoidosis. However, neurosarcoidosis without systemic involvement is extremely rare. We present a case of suspicious neurosarcoidosis affecting the pituitary gland, which was manifested as chronic uncontrolled headache, panhypopituitarism, central diabetes insipidus, and hypercalcemia. Though the biopsy at the pituitary lesion was not performed due to the high risk of surgical complication, treatment was needed urgently and we started steroid therapy. After steroid therapy, we observed the immediate symptom relief with improved hypercalcemia. According to the follow-up examination, no recurrent symptom was seen, and resolution of the pituitary lesion with improving panhypopituitarism was noted.

Evaluation of glycemic variability in well-controlled type 2 diabetes mellitus.

AIMS: It is necessary to evaluate glucose variability and postprandial hyperglycemia in patients with well-controlled type 2 diabetes mellitus because of the limitations associated with hemoglobin A1c (HbA1c) measurements. We evaluated parameters reflecting postprandial hyperglycemia and glycemic variability in patients with optimal HbA1c. PATIENTS AND METHODS: Thirty-nine patients with HbA1c levels below 7% were recruited to the study. A continuous glucose monitoring system (CGMS) was applied for two 72-h periods. 1,5-Anhydroglucitol (1,5-AG) and fructosamine (FA) were measured as parameters for postprandial hyperglycemia and glucose variability. Using CGMS data, the following postprandial hyperglycemia parameters were calculated: mean postprandial maximum glucose (MPMG) and area under the curve for glucose above 180 mg/dL (AUC-180). To measure glycemic variability, we calculated mean amplitude of glucose excursion (MAGE) using a classical (MAGEc) and new method (MAGE group of sign [MAGEgos]). RESULTS: The baseline HbA1c level was 6.3±0.3%. The mean MPMG was 10.34±1.84 mmol/L, and the mean AUC-180 was 0.17±0.23 mmol/L/day. The mean MAGEgos was 3.27±1.29 mmol/L, and MAGEc was 4.30±1.43 mmol/L, indicating glycemic variability in our patients. The mean levels of 1,5-AG and FA were 16.7±7.4 µg/mL and 273.0±22.5 µmol/L, respectively. In a correlation analysis, FA was significantly correlated with MPMG, AUC-180, MAGEgos, and MAGEc. In contrast, 1,5-AG was only correlated with AUC-180. CONCLUSIONS: This study demonstrated postprandial hyperglycemia and glycemic variability in subjects with well-controlled diabetes. FA may reflect postprandial hyperglycemia and glycemic variability, but 1,5-AG may be of limited value for assessing glucose variability in patients with well-controlled type 2 diabetes mellitus.

Autoimmune hypoglycemia in a patient with characterization of insulin receptor autoantibodies.

BACKGROUND: Type B insulin resistance syndrome is a manifestation of autoantibodies to the insulin receptor that results in severe hyperglycemia and acanthosis nigricans. However, the mechanisms by which these autoantibodies induce hypoglycemia are largely unknown. In this paper, we report the case of patient with type B insulin resistance syndrome who presented with frequent severe fasting hypoglycemia and acanthosis nigricans. METHODS: To evaluate the mechanism of hypoglycemia, we measured the inhibition of insulin binding to erythrocytes and IM9 lymphocytes in a sample of the patient's dialyzed serum before and after immunosuppressive therapy. RESULTS: In the patient's pre-treatment serum IgG, the binding of (125)I-insulin to erythrocytes was markedly inhibited in a dose-dependent manner until the cold insulin level reached 10(-9) mol/L. We also observed dose-dependent inhibition of insulin binding to IM9 lymphocytes, which reached approximately 82% inhibition and persisted even when diluted 1:20. After treatment with glucocorticoids, insulin-erythrocyte binding activity returned to between 70% and 80% of normal, while the inhibition of insulin-lymphocyte binding was reduced by 17%. CONCLUSION: We treated a patient with type B insulin resistance syndrome showing recurrent fasting hypoglycemia with steroids and azathioprine. We characterized the patient's insulin receptor antibodies by measuring the inhibition of insulin binding.

A case of multiple endocrine neoplasia type 1 with primary liver gastrinoma.

Gastrinoma is the most frequent functional pancreaticoduodenal endocrine tumor in patients with multiple endocrine neoplasia type 1 (MEN 1). Primary hepatic gastrinomas in MEN 1 are very rare, with no previous reports published in the literature. We reported the case of a 39 yr old female patient with a history of repeated peptic ulcers and a hypoglycemia episode. Abdominal CT indicated a well-defined liver mass and a pancreatic head mass. Somatostatin-receptor scintigraphy with [(111)In] DTPA octreotide demonstrated a strong uptake of the radiotracer in the left lateral segment at the site of the hepatic mass. After operation, immunohistochemical staining was consistent with pancreatic insulinoma and primary hepatic gastrinoma. As the liver is a common site of metastases from gastrinoma, primary liver gastrinoma has not yet been reported with MEN 1. We diagnosed this patient using immunohistochemical studies and treated this patient by hepatic segmentectomy.

Kaempferol protects HIT-T15 pancreatic beta cells from 2-deoxy-D-ribose-induced oxidative damage.

During the progression of Type 2 diabetes, glucose toxicity is likely to contribute importantly to progressive beta cell failure. Oxidative stress is an important aspect of glucose toxicity in pancreatic beta cells, and reducing sugars, such as 2-deoxy-D-ribose (dRib), produce reactive oxygen species. Furthermore, many of the biological properties of flavonoids are likely to be related to their antioxidant and free-radical scavenging abilities. Accordingly, in the present study, we investigated whether kaempferol (a flavonol) protects beta cells from dRib-induced oxidative damage. HIT-T15 cells were cultured with various concentrations of dRib for 24h. Cell survivals, amounts of reactive oxygen species (ROS) generated, apoptosis, and lipid peroxidation were measured. dRib was found to dose-dependently reduce cell survival and to markedly increase intracellular ROS levels, apoptosis, and lipid peroxidation. However, kaempferol (10 microM) suppressed dRib (20 mM) induced intracellular ROS, apoptosis, and lipid peroxidation. So, we demonstrate that kaempferol reduces dRib-mediated beta cell damage interfering with ROS metabolism and protective effects against lipid peroxidation. Our findings indicate that kaempferol protects HIT-T15 cells from dRib-induced associated oxidative damage.